A communication terminal apparatus, communication system, communication method, and program are provided that enable a decoding section of a mobile communication apparatus to be controlled and operated only when necessary even when receive data retransmission occurs. A radio communication apparatus is equipped with a radio antenna, a demodulation section that performs demodulation of receive data, a data combining section that combines the demodulated data with past data, a decoding section that decodes the combined data, an error correction section that performs error correction processing using the decoded data, an error determination section that determines a data error using the data on which error correction processing has been performed, a transmitting section, a retransmission determination section that determines data reliability and the number of retransmission requests based on the communication state of receive data, and a control section that controls each of the above sections, and control section stops the operation of decoding section and subsequent sections until data reliability determined by retransmission determination section exceeds a predetermined threshold value.